import "package:flutter/material.dart";
import 'package:oktoast/oktoast.dart';

class MyHomePage extends StatefulWidget {
    MyHomePage({Key key, this.title}) : super(key: key);
    
    // This widget is the home page of your application. It is stateful, meaning
    // that it has a State object (defined below) that contains fields that affect
    // how it looks.
    
    // This class is the configuration for the state. It holds the values (in this
    // case the title) provided by the parent (in this case the App widget) and
    // used by the build method of the State. Fields in a Widget subclass are
    // always marked "final".
    
    final String title;
    
    @override
    _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
    int _counter = 0;
    
    void _incrementCounter() {
        setState(() {
            // This call to setState tells the Flutter framework that something has
            // changed in this State, which causes it to rerun the build method below
            // so that the display can reflect the updated values. If we changed
            // _counter without calling setState(), then the build method would not be
            // called again, and so nothing would appear to happen.
            _counter++;
        });
    }
    
    @override
    Widget build(BuildContext context) {
        // This method is rerun every time setState is called, for instance as done
        // by the _incrementCounter method above.
        //
        // The Flutter framework has been optimized to make rerunning build methods
        // fast, so that you can just rebuild anything that needs updating rather
        // than having to individually change instances of widgets.
        return Scaffold(
            appBar: PreferredSize(
                preferredSize: Size.fromHeight(36.0), // here the desired height
                child: AppBar(
                    centerTitle: true,
                    elevation: 0.5,
                    titleSpacing: 0.0,
                    title: Text(widget.title),
                ),
            ),
            body: Center(
                // Center is a layout widget. It takes a single child and positions it
                // in the middle of the parent.
                child: Column(
                    // Column is also layout widget. It takes a list of children and
                    // arranges them vertically. By default, it sizes itself to fit its
                    // children horizontally, and tries to be as tall as its parent.
                    //
                    // Invoke "debug painting" (press "p" in the console, choose the
                    // "Toggle Debug Paint" action from the Flutter Inspector in Android
                    // Studio, or the "Toggle Debug Paint" command in Visual Studio Code)
                    // to see the wireframe for each widget.
                    //
                    // Column has various properties to control how it sizes itself and
                    // how it positions its children. Here we use mainAxisAlignment to
                    // center the children vertically; the main axis here is the vertical
                    // axis because Columns are vertical (the cross axis would be
                    // horizontal).
                    mainAxisAlignment: MainAxisAlignment.center,
                    children: <Widget>[
                        Text(
                            '你点了那个按钮 $_counter 次',
                            style: Theme.of(context).textTheme.display1,
                        ),
                    ],
                ),
            ),
            floatingActionButton: FloatingActionButton(
                onPressed: _incrementCounter,
                tooltip: 'Increment',
                child: Icon(Icons.add),
            ), // This trailing comma makes auto-formatting nicer for build methods.
        );
    }
}